Does Too Much Exercise Cause Infertility?

Today's focus on fitness has heightened awareness for many people about the benefits of maintaining a regular exercise routine. But is it possible to overdo it?

Absolutely, say medical experts, especially if you are trying to conceive.

According to The American Society for Reproductive Medicine, researchers have found there may be a connection between vigorous exercise at increasing levels and the length of time it takes to become pregnant, at least for healthy women of average weight. Running, fast cycling, aerobics, gymnastics, and swimming were considered by the researchers to be vigorous activity.

Interestingly, obese women or those who are significantly overweight do not experience the same delays if they participate in regular vigorous activity.

The researchers also found that slight decreases in the time it takes to conceive tend to occur with moderate levels of exercise--activities like brisk walking, leisurely cycling, golfing, and gardening--regardless of a woman's body mass index (the amount of fat in a person's body, based on her weight and height).

The study included responses from over 3,000 women, ages 18 to 40, who were in stable relationships and hoping to become pregnant. None of the participants were receiving fertility treatments. The women were asked how many hours they exercised each week, and how many of those hours were spent in various types of vigorous or moderate activities. The results showed that average-weight participants who regularly engaged in vigorous physical activity took longer overall to become pregnant than women who did not.

The good news is that the study also suggests that participants who exercise moderately for 20 to 39 hours per week are able to conceive the most quickly.

PreconceptionWeekly.com also reports that extreme exercise can interfere with conception by inhibiting ovulation or interfering with implantation of the the fertilized egg. According to a report on the website, too much or too little body fat can cause a hormonal imbalance, since about 30% of the estrogen in a woman's body is produced from fat cells. Maintaining a healthy weight can help a woman keep her hormones in balance.

Women who engage in too much regular vigorous activity can end up with so little body fat that they develop an estrogen deficiency and begin to miss periods, according to PreconceptionWeekly.com, or even stop having periods altogether. Being underweight or losing a lot of weight quickly can also cause a decreased level of hormones responsible for the development of eggs in the ovaries.

On the other hand, regular exercise reduces stress and elevates your mood. High stress levels can actually inhibit ovulation and cause an irregular menstruation pattern, which can delay conception. And of course, regular moderate exercise keeps you feeling fit and more confident about your appearance, which can increase your desire for intimacy with your partner.

While many factors can affect your ability to conceive, moderate exercise and healthy food choices seem to lead the pack, according to most reports. A recent article by USA Today cites a study by researchers at the Harvard School of Public Health that lists eight steps to increase fertility. The study found that women who followed five or more of the steps experienced 80% less risk of infertility due to ovulation disorders. The list included pointers like making healthy food choices, maintaining a healthy weight, and exercising for 30 minutes each day.

So the fact still remains: Exercise is good for you, before during, and after pregnancy. But if you are trying to conceive--and while you are pregnant--moderation may be the key to getting pregnant quickly, maintaining a healthy pregnancy weight, and losing the weight and staying fit post-pregnancy.